Background
Objective
Study Design
Results
Conclusion
Key words
Introduction
Why was this study conducted?
Key findings
What does this add to what is known?
Materials and Methods
Study populations
Exchange rate between benefit and harm from use of aspirin
R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.
Results
Net benefit
Determination of risk cutoffs
Exchange rate | RRR | ||||
---|---|---|---|---|---|
0.2 | 0.4 | 0.6 | 0.8 | 1 | |
10 | 1 in 2 | 1 in 4 | 1 in 6 | 1 in 8 | 1 in 10 |
50 | 1 in 10 | 1 in 20 | 1 in 30 | 1 in 40 | 1 in 50 |
100 | 1 in 20 | 1 in 40 | 1 in 60 | 1 in 80 | 1 in 100 |
500 | 1 in 100 | 1 in 200 | 1 in 300 | 1 in 400 | 1 in 500 |
1000 | 1 in 200 | 1 in 400 | 1 in 600 | 1 in 800 | 1 in 1000 |
Scenario | Exchange rate E | Risk cutoff | SPR (%) | DR (%) | Per 10,000 | NNT | ||
---|---|---|---|---|---|---|---|---|
Treated | Prevented | Net benefit | ||||||
1 | 10 | 0.1613 (1 in 6) | 0.5 | 20 | 89 | 17.36 | 5.1 (−947.4) | 5.1 |
2 | 150 | 0.0108 (1 in 93) | 11.6 | 83 | 1945 | 73.16 | 35.9 (−14.1) | 26.6 |
3 | 1000 | 0.0016 (1 in 620) | 47.9 | 99 | 8027 | 86.80 | 47 (42.6) | 92.5 |
Net benefits for a screening program

Comment
Main findings
Comparison with previous studies
Limitations
Conclusion
Supplementary Data
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Wright et al. Prevention of preeclampsia by aspirin. Am J Obstet Gynecol 2022.
References
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Article Info
Publication History
Footnotes
The authors report no conflict of interest.
The study was supported by a grant from the Fetal Medicine Foundation (UK charity number: 1037116). The funding body was not involved in the study design; collection, analysis, and interpretation of data; writing of the report; and decision to submit the article for publication.
This paper is part of a supplement.